Q: Is 421,720 a Prime Number?
A: No, 421,720 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 421720 can be evenly divided by 1 2 4 5 8 10 13 20 26 40 52 65 104 130 260 520 811 1,622 3,244 4,055 6,488 8,110 10,543 16,220 21,086 32,440 42,172 52,715 84,344 105,430 210,860 and 421,720, with no remainder.
Since 421,720 cannot be divided by just 1 and 421,720, it is not a prime number.